Compass Swings
You're never too old to learn something new, but as an old Nav Insty, I think it would have been a bit tricky to set up a Medium Landing Compass (or worse still, a Watts Datum Compass) behind an airborne fixed wing aircraft. Might just have got away with it with a helicopter, had enough beer been on offer.
Fixed landmarks - better than nothing but you'd need at least four at the cardinal points to get any sort of accuracy...